Seeing at night - settings

[Fairyshine 3,183]

I remember a long time ago I set something to "off" or unticked, and the side effect was that night was much lighter.  It also turned black caves into areas where I could see what is going on.  Could someone wiser than me please let me know what the setting is to achieve this?  Thanks very much!

[Niki 2,278]

I think the game should have a gamma option, I'd prefer the game to be darker for example.

[cybaru 42]

Display Brightness under Graphic setting tab?